Chevrolet Tech needed.

[UncleSteve]

my 04 Avalanche 1/2 ton has a "service 4WD" message in the message center


4wd inoperative. None of the switches for the 4wd light up.
I had one person tell me there is a module of some kind out and it is a $300 part.
Anyone experience the similar problem?

 

[head east busa]

possibly the 4wd switch in the dash believe it or not yes that's a possibility also check for recalls on it

 

[zukracer]

I've had it on mine a bunch, check your drive selection before moving along, I found myself driving quite too fast in 4lo once ???

www.chevyavalanchefanclub.com should give you most anything you need to know about your truck

 

[head east busa]

Hers a start

* TSB #05-04-21-003 -- SERVICE 4WD LIGHT ILLUMINATED, DIAGNOSTIC TROUBLE CODE (DTC) C0374 SET. *TT UPDATED 10/05/07. *NJ INSPECT WIRING HARNESS TO TRANSFER CASE SPEED SENSORS, REPLACE WIRING HARNESS. UPDATED 7/18/08 *PE (NHTSA ID #10017464, JANUARY 01 2008)
* TSB #020421006C -- INOPERATIVE 4WD/AWD LAMPS, INOPERATIVE 4WD/AWD SYSTEM. *TT (NHTSA ID #10004357, MARCH 01 2004)
* TSB #01267A -- SERVICE 4WD LIGHT ON, THE 4WD IS INOPERATIVE AND NO CODES BESIDES U1000 CODES. SERVICE VME. *TT (NHTSA ID #10004104, NOVEMBER 18 2003)
* TSB #01267B -- SERVICE 4WD LIGHT ON NO CODES BESIDES U1000 CODES. SERVICE VME. *TT (NHTSA ID #10004200, NOVEMBER 18 2003)
* TSB #3526 -- INTERMITTENT SERVICE 4WD LIGHT COMES ON WITH DIAGNOSTIC TROUBLE CODE (DTC) C0306 OR C0308 STORED IN TCCM. *TT (NHTSA ID #10016558, no date provided)
* TSB #3665 -- 4WD INOPERATIVE AND POSSIBLE DTC C0327 STORED IN THE TRANSFER CASE CONTROL MODULE. *TT (NHTSA ID #10018926, no date provided)
* TSB #3424 -- ELECTRONIC TRANSFER CASE UNABLE TO COMPLETE SHIFT. *TT (NHTSA ID #10017299, no date provided)
* TSB #3351 -- INTERMITTENT MALFUNCTION INDICATOR LAMP (MIL) WITH DIAGNOSTIC TROUBLE CODE (DTC) C0374 OR ERRATIC 4WD/AWD OPERATION. *TT (NHTSA ID #10014853, no date provided)

 

[head east busa]

I've had it on mine a bunch, check your drive selection before moving along, I found myself driving quite too fast in 4lo once ???

www.chevyavalanchefanclub.com should give you most anything you need to know about your truck

Here's a thread that should help


Service 4WD message
« Reply #2 on: 08/08/03 08:52 AM »

I had the same thing happen; hit a deep puddle then a while later the Service 4WD warning came on and none of the 2/4WD indicators would light. It was fine the next day, but the dealer replace the control unit anyway. He said there's a GM tech note out for the Silverados, but they'd been seeing the same thing happen to Suburbans and Tahoes also. And now, of course, Avalanches.

It hasn't come back, so yeah, it's fixed to my satisfaction.

 

[BA BUSA]

Check the fluid level in the transfer case ???

 

[Bosshound]

my 04 Avalanche 1/2 ton has a "service 4WD" message in the message center


4wd inoperative. None of the switches for the 4wd light up.
I had one person tell me there is a module of some kind out and it is a $300 part.
Anyone experience the similar problem?

What Happened Before the Light ? Did you hit a Pot Hole ? Had it in 4WD ?

Try Disconnecting the Battery for about 1 Minute and See what Happens.........???

 

[UncleSteve]

What Happened Before the Light ? Did you hit a Pot Hole ? Had it in 4WD ?

Try Disconnecting the Battery for about 1 Minute and See what Happens.........???

I have not used the 4wd in a long time, no pot holes, maybe rain had something to do with it. It came on a few months ago and went off for a long time and then came on intermittent, with no real reason. I don't drive it often. 27k miles on it.
I can tell you this.... the most expensive part will be the one I need.
Probably best to start with it first and go from there.

 

[B@DA$$08BUS@]

I have not used the 4wd in a long time, no pot holes, maybe rain had something to do with it. It came on a few months ago and went off for a long time and then came on intermittent, with no real reason. I don't drive it often. 27k miles on it.
I can tell you this.... the most expensive part will be the one I need.
Probably best to start with it first and go from there.

I know its too late now, but I have always been told by many of different service guys if u own a 4X4 u shoul run it regularly, atleast once a month, that will help keep things lubed upand allow one 2 find smaller problems b4 they become BIGGER ones. Just my 2 cents.
Posted via Mobile Device

 

[SKnight]

You need the position sensor in the transfer case control module. You'll need to be able to clear the code and try to get the transfer case in neutral. If you can't get it in neutral don't worry, just be careful aligning things exactly as they were in the case.

Remove the front drive shaft, use a screwdriver to just push the boot off at the case end. Now remove the module, set it on a table and open it up. Just a few torx screws. Once open you'll see the shaft that drives the case, mark it's position if the timing marks aren't aligned, now lift it out and you'll see a sensor ring around it. That's what you're replacing. Replace the sensor, and reassemble paying close attention to your marks. Put it all together and clear the code.

You can get the position sensor from the dealers and it takes about an hour start to finish. The module is $300+, the sensor is like $50 as I recall.

 

[Silent Shogun]

Ahhh...ive had a few chevy's and this is an easy fix... just find a cliff and drive it off it..

 

[00busaTX]

Mine did the same thing. The most common reason is the lamps on the control unit to the left of the steering wheel. When you turn on the truck, the ECU checks the controls for feed back. If the feed back is not present, it illuminates the dash and shuts down the 4WD. Look for a loose connector behind the panel or a new control unit.

I just punched mine and it has worked ever since.......

*** I do not recommend or condone my course of action, but it did work for me ***

 

[djsin]

i hate the electronic shifty things...like the old pull over and move the lever into 4 wheel drive the best, back then nothing whent wrong..203/205 transfer cases

 

[shadetree57]

i hate the electronic shifty things...like the old pull over and move the lever into 4 wheel drive the best, back then nothing whent wrong..203/205 transfer cases

You Are Right, Mine has the shifter and I like it better.

 

[Busa1166]

my 04 Avalanche 1/2 ton has a "service 4WD" message in the message center


4wd inoperative. None of the switches for the 4wd light up.
I had one person tell me there is a module of some kind out and it is a $300 part.
Anyone experience the similar problem?

Before you start buying electrical parts which are usually not returnable a tech2 diagnostic test might save you some time an money

 

[UncleSteve]

You need the position sensor in the transfer case control module. You'll need to be able to clear the code and try to get the transfer case in neutral. If you can't get it in neutral don't worry, just be careful aligning things exactly as they were in the case.

Remove the front drive shaft, use a screwdriver to just push the boot off at the case end. Now remove the module, set it on a table and open it up. Just a few torx screws. Once open you'll see the shaft that drives the case, mark it's position if the timing marks aren't aligned, now lift it out and you'll see a sensor ring around it. That's what you're replacing. Replace the sensor, and reassemble paying close attention to your marks. Put it all together and clear the code.

You can get the position sensor from the dealers and it takes about an hour start to finish. The module is $300+, the sensor is like $50 as I recall.

So, I need the module and the sensor?

 

[SKnight]

Nope, just the sensor. Most people don't want to take them apart, so they have the module available.

I neglected to mention, see if you can get it scanned first, as I recall the code in question is a C0327, any code described as a range fault will need that sensor. That's all that ever went wrong with the new body style for the most part. At least electrically.